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The CPT® Code 81318 pertains to the molecular genetic testing of the PMS2 gene, specifically focusing on known familial variants. This testing is crucial for identifying mutations that increase an individual's risk of developing hereditary non-polyposis colorectal cancer (HNPCC), commonly referred to as Lynch syndrome. The PMS2 gene, located on chromosome 7, plays a vital role in encoding proteins responsible for DNA repair. When mutations occur in this gene, they can lead to the production of an abnormally short or inactive PMS2 protein, which is less effective at repairing DNA. Over time, the accumulation of unrepaired DNA errors can result in the proliferation of cells into tumors, significantly raising the risk of colorectal and other cancers. The specific mutation associated with PMS2 can also lead to a rare variant of Lynch syndrome known as Turcot syndrome, which is characterized by the development of brain tumors, such as glioblastoma, alongside colorectal cancer. It is important to note that some individuals may develop HNPCC 'de novo,' meaning the mutation arises spontaneously in the germ cell or fertilized egg, rather than being inherited from a parent. In contrast to the full sequence analysis performed under CPT® Code 81317, which compares gene segments to identify similarities and relationships, CPT® Code 81318 focuses on testing for known familial variants. This is particularly beneficial for family members of individuals diagnosed with PMS2 mutations, as it can help identify common variants and assess the risk factors for relatives who may share the same genetic mutation. Additionally, CPT® Code 81319 addresses the testing for PMS2 duplication or deletion variants, which are critical for understanding the genetic landscape of the PMS2 gene. Overall, the testing under CPT® Code 81318 is an essential tool in the early detection and management of hereditary cancer risks associated with PMS2 mutations.
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Hereditary Non-Polyposis Colorectal Cancer (HNPCC) Genetic testing is indicated for individuals with a family history of HNPCC or Lynch syndrome, as it helps identify those at increased risk of developing colorectal and other associated cancers.
Known Familial Variants Testing is performed when a specific PMS2 mutation has been identified in a family member, allowing for the assessment of other relatives for the same or similar genetic variants.
Turcot Syndrome Individuals presenting with symptoms of Turcot syndrome, which includes both colorectal cancer and brain tumors such as glioblastoma, may be candidates for PMS2 gene analysis to confirm the presence of mutations.
Step 1: Sample Collection The procedure begins with the collection of a biological sample, typically blood or saliva, from the individual undergoing testing. This sample contains the DNA necessary for genetic analysis.
Step 2: DNA Extraction Once the sample is collected, DNA is extracted from the cells within the sample. This process involves breaking down the cell membranes and isolating the DNA for further analysis.
Step 3: Genetic Testing for Known Variants The extracted DNA is then subjected to molecular genetic testing specifically designed to identify known familial variants of the PMS2 gene. This testing focuses on previously identified mutations that have been documented in family members.
Step 4: Data Analysis After the genetic testing is completed, the results are analyzed to determine the presence of any known PMS2 mutations. This analysis may involve comparing the individual's genetic data against established databases of known variants.
Step 5: Reporting Results Finally, the results of the genetic testing are compiled into a report, which is provided to the healthcare provider. This report will indicate whether any known familial variants were detected and may include recommendations for further testing or family counseling.
After the genetic testing procedure, individuals may receive counseling to discuss the implications of the test results. If a known familial variant is identified, family members may also be encouraged to undergo testing to assess their risk. Additionally, healthcare providers may recommend regular screening and surveillance for colorectal cancer and other associated cancers based on the results. It is important for individuals to understand the potential emotional and psychological impacts of genetic testing, and support services may be offered to assist them in coping with the results.
| Short Descr | PMS2 KNOWN FAMILIAL VARIANTS | Medium Descr | PMS2 GENE ANALYSIS KNOWN FAMILIAL VARIANTS | Long Descr | PMS2 (postmeiotic segregation increased 2 [S. cerevisiae]) (eg, hereditary non-polyposis colorectal cancer, Lynch syndrome) gene analysis; known familial variants | Status Code | Statutory Exclusion (from MPFS, may be paid under other methodologies) | Global Days | XXX - Global Concept Does Not Apply | PC/TC Indicator (26, TC) | 9 - Not Applicable | Multiple Procedures (51) | 9 - Concept does not apply. | Bilateral Surgery (50) | 9 - Concept does not apply. | Physician Supervisions | 09 - Concept does not apply. | Assistant Surgeon (80, 82) | 9 - Concept does not apply. | Co-Surgeons (62) | 9 - Concept does not apply. | Team Surgery (66) | 9 - Concept does not apply. | Diagnostic Imaging Family | 99 - Concept Does Not Apply | CLIA Waived (QW) | No | APC Status Indicator | Service Paid under Fee Schedule or Payment System other than OPPS | Type of Service (TOS) | 5 - Diagnostic Laboratory | Berenson-Eggers TOS (BETOS) | T1H - Lab tests - other (non-Medicare fee schedule) | MUE | 1 | CCS Clinical Classification | 234 - Pathology |
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| 2012-01-01 | Added | Added |
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